Function newton_rootfinder::xml_parser::from_xml_finite_diff

pub fn from_xml_finite_diff(
    filepath: &str
) -> (SolverParameters, Vec<IterativeParamsFD>, Vec<NormalizationMethod>, Vec<NormalizationMethod>)

Parser for a solver operating with a model with the jacobian not provided

The use of finite difference requires additional parameters for the iteratives variables.

The three additional parameters are:

• dx_abs
• dx_rel
• perturbation_method

Otherwise, it works in exactly the same way as the super::from_xml_jacobian parser. Refers to this doc for the general explanation. The differences are highlighted here

The <iteratives> node takes the 3 extra arguments as default values. This values can be overwritten in the same way

 <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
 <nrf>
     <solver>...</solver>
     <iteratives min_value="-inf" max_value="inf" max_step_abs="inf" max_step_rel="inf" dx_abs="1.5e-6" dx_rel="5e-5" perturbation_method="Max">
         <iterative id="0" perturbation_method="Sum">
         <iterative id="1" max_step_abs="100">
     </iteratives>
     <residuals>...</residuals>
 </nrf>